Stokes camera with wide field of view by fisheye lens

We demonstrate a wide field of view Stokes camera using a fisheye lens and an RGB microgrid polarization camera having a linear micro-polarizer array aligned to 0, 45, 90, and 135° azimuthal directions. The wide field of view lens introduces significant field-dependent polarization effects, so that a careful calibration is needed. This paper presents a compensation method based on Stokes parameters and Mueller matrices to address this challenge. We construct a wide-field scene with known polarization signature, from which we can then estimate the field angle dependent Mueller matrix of the fisheye lens. Compensating for the lens then involves a pixel-by-pixel inverse matrix computation. We show experimental results of a high-resolution partial Mueller matrix model (3×3 matrix per pixel) that accounts for the fisheye lens’ polarization properties, enabling precise polarization correction, and show the correction applied to wide-field sky polarization measurement.